In biometric authentication technologies such as fingerprint authentication and vein authentication, the finger of an authentication subject must be appropriately placed on a placement surface on which the finger is to be placed, in order to allow the fingerprint or the vein pattern of the authentication subject to be collated with pre-registered authentication data.
For example, Patent Document 1 describes a biometric authentication method wherein a fingertip sensor for detecting misalignment of the finger placement position is provided on a tip placement surface of a tip placement unit on which the inside tip of a finger is to be placed, whereby misalignment of the inside tip of the finger is detected and the user is notified of misalignment of the finger placement position.
Additionally, in recent years, so-called wearable terminals, in which an information terminal is installed in a device that is worn on the body, such as a wristwatch, eyeglasses, a wristband or a finger ring (ring), have been provided. Wearable terminals often store information regarding the individual wearing that terminal, and mechanisms for authenticating whether or not they are being worn by the owner have been sought for security purposes.
Consider examples in which biometric authentication technologies are used in wearable terminals. For example, in the case of a wristwatch-type wearable terminal, an authentication method wherein a unit for fingerprint authentication is installed in the wearable terminal and fingerprint authentication is performed, for example, when a user places a finger on the display unit of the wristwatch, might be contemplated.